Easily localized

Poorly localized conducting A-delta fibers. Because fast pain is elicited by stimulation of specific thermal or mechanical nociceptors, it is easily localized. This type of pain is not felt in most of the deeper tissues of the body. Slow pain may be described as dull, aching, or throbbing pain. This pain is perceived second (only after 1 sec or more) because it is carried by C fibers. Slow pain persists longer and is typically more unpleasant; in fact, it tends to become greater over time. Slow pain is typically associated with tissue destruction. Noxious chemicals released from damaged cells or activated in the interstitial fluid can spread in the tissue, causing a relatively diffuse stimulation of polymodal receptors. As a result, slow pain is poorly localized; it may occur in the skin as well as almost any deep tissue or organ.

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.